Dan has 140 markers. How many more boxes of 10 markers does he need to get so that he will have 180 markers in all?
The difference between 180 and 140 is 180 - 140 = <<180-140=40>>40.
Therefore, Dan needs 40 / 10 = <<40/10=4>>4 more boxes of markers. Answer: \boxed{4}.
To solve this problem, we need to calculate how many more markers Dan needs to reach a total of 180.
Step 1: Find out how many markers Dan currently has:
Dan has 140 markers.
Step 2: Calculate how many more markers Dan needs:
The desired total is 180 markers.
Subtract the number of markers Dan already has from the desired total: 180 - 140 = 40.
Step 3: Determine how many boxes of 10 markers Dan needs:
Each box contains 10 markers.
Divide the number of additional markers needed by the number of markers in each box: 40 / 10 = 4.
Step 4: Answer the question:
Dan needs 4 more boxes of markers to have a total of 180 markers.